Learn about measles

Measles spreads easily and can be serious

Measles is a very contagious viral disease that spreads through coughing or sneezing. The measles virus can float in the air for up to one hour after someone with measles has coughed or sneezed. People with measles can spread the disease to others from 4 days before the rash starts (before they know they have the disease), through 4 days after the rash begins. Measles can cause serious disease, especially in children. Learn more about measles from CDPH.

Prevent measles with the MMR vaccine

The best protection against measles is the measles-mumps-rubella (MMR vaccine). Adults (aged 19 years and older) born on or after 1957 should get at least one dose of the MMR vaccine to protect against measles. Some adults, such as those who work or volunteer in health care settings, may need a second dose of MMR vaccine. Children should get 2 doses of MMR vaccine. MMR is safe and effective. Two doses provide 97% protection against measles.

Check your vaccination status

Not sure if you've had the MMR vaccine? Check with your provider, or find out how to get a copy of your vaccine record.

If you need MMR vaccine and aren't sure where to go in San Francisco, visit Get vaccines.

Call your doctor or clinic if you have measles symptoms

Measles starts with fever, cough, runny nose, and red, watery eyes. After a few days a rash develops on the face and spreads to other parts of the body.

Call ahead to tell your doctor that you have measles symptoms before you go to the clinic. They will help you get to the clinic in a safe way to prevent measles from spreading in the waiting room.

Suspect measles in patients with:

• Fever, rash and any of the “3 Cs" – cough, coryza, or conjunctivitis
• In the prior 3 weeks, any of:
  • Attendance of an event or location with a known measles exposure
  • International travel
  • Transit through airports
  • Potential interactions with international visitors at theme parks or other settings in the U.S.​

Mask and isolate patients presenting with fever and rash immediately

• Isolate and mask the patient immediately in an Airborne Infection Isolation Room (AIIR) if possible. If an AIIR is not available, place the patient in a single person exam room with door closed.
• Notify infection control at your facility.

Collect throat or NP swab and urine for PCR testing at the SFDPH Public Health Laboratory

Collecting specimens while the patient is at your facility will prevent delays in confirmation of the diagnosis and limit the potential for additional healthcare visits/exposures. Once specimens are obtained, please hold them and SFDPH Communicable Disease (628-217-6100) will instruct on next steps. If approved, specimens will be tested at the SFDPH Public Health Laboratory.

Additional resources for providers:

• CDPH Health Alert: Increase of Measles in California
• Guide: Should I Test for Measles (CDPH)
• SF Public Health Laboratory measles PCR test order
• Measles Investigation Quicksheet (CDPH)
• Measles Healthcare Exposure Investigation Quicksheet (CDPH)
• Measles (CDPH)
• Measles Resources – California Vaccines for Children (VFC)

The short URL for this page is SF.gov/measles